A circuit for driving a light-emitting device or a liquid crystal device, an integrated circuit having a function of arithmetic processing, or the like is manufactured by stacking various layers such as a conductive layer, an insulating layer, or a semiconductor layer. Therefore, variations of the height of a surface from a reference surface due to difference in lamination structures, that is, a level difference are produced. When the level difference is increased, it becomes difficult to form a layer for covering the level difference and deterioration such as stepped cut of a wiring may be produced. In the light-emitting device, there may be difference in an emission spectrum of light emission extracted to the outside due to the level difference.
Therefore, technique that a surface is planarized by a chemical mechanical polishing method or the like or a layer is formed by a material having a self-planarization property such as acrylic, polyimide, or siloxane has been developed.
Development of technique for processing a formed layer is required with advance in development of technique for relieving level difference by forming a layer which is planarized its surface. For example, a patent document 1 discloses technique of etching an organic siloxane film by using a processing gas such as CF4, N2, and Ar.